Aloisi indicated at a press conference on Thursday that he never got the chance to decide on Broich's future at the club before the German confirmed he would leave to continue his career elsewhere.
Broich revealed this week that he will leave Roar at the end of the 2016-17 campaign after seven consecutive seasons in orange, with the 36-year-old claiming he couldn't wait to see if Brisbane wanted to extend his contract.
BROICH UNFAZED BY LOOMING EXIT
It means the attacking midfielder may play his last home A-League game for Brisbane against the Wanderers.
When asked about Broich's mind-set heading into the knockout clash, Aloisi rejected any notion the veteran would lack concentration.
"At the beginning of the season and halfway through the season, he wasn't sure whether he wanted to play on but just a couple of weeks ago he decided that he did and I didn't even make a decision," Aloisi said.
"It was something that Thomas made and we respect that and now we're just focused on the game.
"I spoke to him yesterday afternoon, gave him a call to see how he was and he said 'I'm preparing exactly the same like I would any other game' and that's all I wanted to hear."
SALARY CAP ISSUES
On Wednesday, Roar's football operations manager Craig Moore said keeping Broich - who would have had to move under the salary cap next season - could have cost the club a player for the future like midfielder Joe Caletti.
A-League clubs are allowed to spend up to $200,000 over the competition's salary cap of $2.6million to retain players that have played five or more consecutive seasons with the club but it has been reported that Brisbane have already used that money to keep others.
Aloisi wasn't willing to get into the details of why Roar were unable to retain Broich.
"The salary cap restricts you. There's no two ways about it," Brisbane's boss said.
"It's very difficult to explain to the general public what goes on behind closed doors but Thomas Broich for me has been a joy to coach. I get along really well with Thomas."
Broich has played 179 games for Brisbane, winning three A-League championships and two Johnny Warren Medals as the competition's best player.